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/*
* Copyright (c) 2016 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <vnet/dpo/load_balance.h>
#include <vnet/dpo/load_balance_map.h>
#include <vnet/dpo/drop_dpo.h>
#include <vppinfra/math.h> /* for fabs */
#include <vnet/adj/adj.h>
#include <vnet/adj/adj_internal.h>
#include <vnet/fib/fib_urpf_list.h>
#include <vnet/bier/bier_fwd.h>
#include <vnet/fib/mpls_fib.h>
#include <vnet/ip/ip4_inlines.h>
#include <vnet/ip/ip6_inlines.h>
// clang-format off
/*
* distribution error tolerance for load-balancing
*/
const f64 multipath_next_hop_error_tolerance = 0.1;
static const char *load_balance_attr_names[] = LOAD_BALANCE_ATTR_NAMES;
/**
* the logger
*/
vlib_log_class_t load_balance_logger;
#define LB_DBG(_lb, _fmt, _args...) \
{ \
vlib_log_debug(load_balance_logger, \
"lb:[%U]:" _fmt, \
format_load_balance, load_balance_get_index(_lb), \
LOAD_BALANCE_FORMAT_NONE, \
##_args); \
}
/**
* Pool of all DPOs. It's not static so the DP can have fast access
*/
load_balance_t *load_balance_pool;
/**
* The one instance of load-balance main
*/
load_balance_main_t load_balance_main = {
.lbm_to_counters = {
.name = "route-to",
.stat_segment_name = "/net/route/to",
},
.lbm_via_counters = {
.name = "route-via",
.stat_segment_name = "/net/route/via",
}
};
f64
load_balance_get_multipath_tolerance (void)
{
return (multipath_next_hop_error_tolerance);
}
static inline index_t
load_balance_get_index (const load_balance_t *lb)
{
return (lb - load_balance_pool);
}
static inline dpo_id_t*
load_balance_get_buckets (load_balance_t *lb)
{
if (LB_HAS_INLINE_BUCKETS(lb))
{
return (lb->lb_buckets_inline);
}
else
{
return (lb->lb_buckets);
}
}
static load_balance_t *
load_balance_alloc_i (void)
{
load_balance_t *lb;
u8 need_barrier_sync = 0;
vlib_main_t *vm = vlib_get_main();
ASSERT (vm->thread_index == 0);
pool_get_aligned_will_expand (load_balance_pool, need_barrier_sync,
CLIB_CACHE_LINE_BYTES);
if (need_barrier_sync)
vlib_worker_thread_barrier_sync (vm);
pool_get_aligned(load_balance_pool, lb, CLIB_CACHE_LINE_BYTES);
clib_memset(lb, 0, sizeof(*lb));
lb->lb_map = INDEX_INVALID;
lb->lb_urpf = INDEX_INVALID;
if (need_barrier_sync == 0)
{
need_barrier_sync += vlib_validate_combined_counter_will_expand
(&(load_balance_main.lbm_to_counters),
load_balance_get_index(lb));
need_barrier_sync += vlib_validate_combined_counter_will_expand
(&(load_balance_main.lbm_via_counters),
load_balance_get_index(lb));
if (need_barrier_sync)
vlib_worker_thread_barrier_sync (vm);
}
vlib_validate_combined_counter(&(load_balance_main.lbm_to_counters),
load_balance_get_index(lb));
vlib_validate_combined_counter(&(load_balance_main.lbm_via_counters),
load_balance_get_index(lb));
vlib_zero_combined_counter(&(load_balance_main.lbm_to_counters),
load_balance_get_index(lb));
vlib_zero_combined_counter(&(load_balance_main.lbm_via_counters),
load_balance_get_index(lb));
if (need_barrier_sync)
vlib_worker_thread_barrier_release (vm);
return (lb);
}
static u8*
load_balance_format (index_t lbi,
load_balance_format_flags_t flags,
u32 indent,
u8 *s)
{
vlib_counter_t to, via;
load_balance_t *lb;
dpo_id_t *buckets;
u32 i;
lb = load_balance_get(lbi);
vlib_get_combined_counter(&(load_balance_main.lbm_to_counters), lbi, &to);
vlib_get_combined_counter(&(load_balance_main.lbm_via_counters), lbi, &via);
buckets = load_balance_get_buckets(lb);
s = format(s, "%U: ", format_dpo_type, DPO_LOAD_BALANCE);
s = format(s, "[proto:%U ", format_dpo_proto, lb->lb_proto);
s = format(s, "index:%d buckets:%d ", lbi, lb->lb_n_buckets);
s = format(s, "uRPF:%d ", lb->lb_urpf);
if (lb->lb_flags)
{
load_balance_attr_t attr;
s = format(s, "flags:[");
FOR_EACH_LOAD_BALANCE_ATTR(attr)
{
if (lb->lb_flags & (1 << attr))
{
s = format (s, "%s", load_balance_attr_names[attr]);
}
}
s = format(s, "] ");
}
s = format(s, "to:[%Ld:%Ld]", to.packets, to.bytes);
if (0 != via.packets)
{
s = format(s, " via:[%Ld:%Ld]",
via.packets, via.bytes);
}
s = format(s, "]");
if (INDEX_INVALID != lb->lb_map)
{
s = format(s, "\n%U%U",
format_white_space, indent+4,
format_load_balance_map, lb->lb_map, indent+4);
}
for (i = 0; i < lb->lb_n_buckets; i++)
{
s = format(s, "\n%U[%d] %U",
format_white_space, indent+2,
i,
format_dpo_id,
&buckets[i], indent+6);
}
return (s);
}
u8*
format_load_balance (u8 * s, va_list * args)
{
index_t lbi = va_arg(*args, index_t);
load_balance_format_flags_t flags = va_arg(*args, load_balance_format_flags_t);
return (load_balance_format(lbi, flags, 0, s));
}
static u8*
format_load_balance_dpo (u8 * s, va_list * args)
{
index_t lbi = va_arg(*args, index_t);
u32 indent = va_arg(*args, u32);
return (load_balance_format(lbi, LOAD_BALANCE_FORMAT_DETAIL, indent, s));
}
flow_hash_config_t
load_balance_get_default_flow_hash (dpo_proto_t lb_proto)
{
switch (lb_proto)
{
case DPO_PROTO_IP4:
case DPO_PROTO_IP6:
return (IP_FLOW_HASH_DEFAULT);
case DPO_PROTO_MPLS:
return (MPLS_FLOW_HASH_DEFAULT);
case DPO_PROTO_ETHERNET:
case DPO_PROTO_BIER:
case DPO_PROTO_NSH:
break;
}
return (0);
}
static load_balance_t *
load_balance_create_i (u32 num_buckets,
dpo_proto_t lb_proto,
flow_hash_config_t fhc)
{
load_balance_t *lb;
lb = load_balance_alloc_i();
lb->lb_hash_config = fhc;
lb->lb_n_buckets = num_buckets;
lb->lb_n_buckets_minus_1 = num_buckets-1;
lb->lb_proto = lb_proto;
if (!LB_HAS_INLINE_BUCKETS(lb))
{
vec_validate_aligned(lb->lb_buckets,
lb->lb_n_buckets - 1,
CLIB_CACHE_LINE_BYTES);
}
LB_DBG(lb, "create");
return (lb);
}
index_t
load_balance_create (u32 n_buckets,
dpo_proto_t lb_proto,
flow_hash_config_t fhc)
{
return (load_balance_get_index(load_balance_create_i(n_buckets, lb_proto, fhc)));
}
static inline void
load_balance_set_bucket_i (load_balance_t *lb,
u32 bucket,
dpo_id_t *buckets,
const dpo_id_t *next)
{
dpo_stack(DPO_LOAD_BALANCE, lb->lb_proto, &buckets[bucket], next);
}
void
load_balance_set_bucket (index_t lbi,
u32 bucket,
const dpo_id_t *next)
{
load_balance_t *lb;
dpo_id_t *buckets;
lb = load_balance_get(lbi);
buckets = load_balance_get_buckets(lb);
ASSERT(bucket < lb->lb_n_buckets);
load_balance_set_bucket_i(lb, bucket, buckets, next);
}
int
load_balance_is_drop (const dpo_id_t *dpo)
{
load_balance_t *lb;
if (DPO_LOAD_BALANCE != dpo->dpoi_type)
return (0);
lb = load_balance_get(dpo->dpoi_index);
if (1 == lb->lb_n_buckets)
{
return (dpo_is_drop(load_balance_get_bucket_i(lb, 0)));
}
return (0);
}
u16
load_balance_n_buckets (index_t lbi)
{
load_balance_t *lb;
lb = load_balance_get(lbi);
return (lb->lb_n_buckets);
}
void
load_balance_set_fib_entry_flags (index_t lbi,
fib_entry_flag_t flags)
{
load_balance_t *lb;
lb = load_balance_get(lbi);
lb->lb_fib_entry_flags = flags;
}
void
load_balance_set_urpf (index_t lbi,
index_t urpf)
{
load_balance_t *lb;
index_t old;
lb = load_balance_get(lbi);
/*
* packets in flight we see this change. but it's atomic, so :P
*/
old = lb->lb_urpf;
lb->lb_urpf = urpf;
fib_urpf_list_unlock(old);
fib_urpf_list_lock(urpf);
}
index_t
load_balance_get_urpf (index_t lbi)
{
load_balance_t *lb;
lb = load_balance_get(lbi);
return (lb->lb_urpf);
}
const dpo_id_t *
load_balance_get_bucket (index_t lbi,
u32 bucket)
{
load_balance_t *lb;
lb = load_balance_get(lbi);
return (load_balance_get_bucket_i(lb, bucket));
}
static int
next_hop_sort_by_weight (const load_balance_path_t * n1,
const load_balance_path_t * n2)
{
return ((int) n1->path_weight - (int) n2->path_weight);
}
/* Given next hop vector is over-written with normalized one with sorted weights and
with weights corresponding to the number of adjacencies for each next hop.
Returns number of adjacencies in block. */
u32
ip_multipath_normalize_next_hops (const load_balance_path_t * raw_next_hops,
load_balance_path_t ** normalized_next_hops,
u32 *sum_weight_in,
f64 multipath_next_hop_error_tolerance)
{
load_balance_path_t * nhs;
uword n_nhs, n_adj, n_adj_left, i, sum_weight;
f64 norm, error;
n_nhs = vec_len (raw_next_hops);
ASSERT (n_nhs > 0);
if (n_nhs == 0)
return 0;
/* Allocate enough space for 2 copies; we'll use second copy to save original weights. */
nhs = *normalized_next_hops;
vec_validate (nhs, 2*n_nhs - 1);
/* Fast path: 1 next hop in block. */
n_adj = n_nhs;
if (n_nhs == 1)
{
nhs[0] = raw_next_hops[0];
nhs[0].path_weight = 1;
_vec_len (nhs) = 1;
sum_weight = 1;
goto done;
}
else if (n_nhs == 2)
{
int cmp = next_hop_sort_by_weight (&raw_next_hops[0], &raw_next_hops[1]) < 0;
/* Fast sort. */
nhs[0] = raw_next_hops[cmp];
nhs[1] = raw_next_hops[cmp ^ 1];
/* Fast path: equal cost multipath with 2 next hops. */
if (nhs[0].path_weight == nhs[1].path_weight)
{
nhs[0].path_weight = nhs[1].path_weight = 1;
_vec_len (nhs) = 2;
sum_weight = 2;
goto done;
}
}
else
{
clib_memcpy_fast (nhs, raw_next_hops, n_nhs * sizeof (raw_next_hops[0]));
qsort (nhs, n_nhs, sizeof (nhs[0]), (void *) next_hop_sort_by_weight);
}
/* Find total weight to normalize weights. */
sum_weight = 0;
for (i = 0; i < n_nhs; i++)
sum_weight += nhs[i].path_weight;
/* In the unlikely case that all weights are given as 0, set them all to 1. */
if (sum_weight == 0)
{
for (i = 0; i < n_nhs; i++)
nhs[i].path_weight = 1;
sum_weight = n_nhs;
}
/* Save copies of all next hop weights to avoid being overwritten in loop below. */
for (i = 0; i < n_nhs; i++)
nhs[n_nhs + i].path_weight = nhs[i].path_weight;
/* Try larger and larger power of 2 sized adjacency blocks until we
find one where traffic flows to within 1% of specified weights. */
for (n_adj = max_pow2 (n_nhs); ; n_adj *= 2)
{
error = 0;
norm = n_adj / ((f64) sum_weight);
n_adj_left = n_adj;
for (i = 0; i < n_nhs; i++)
{
f64 nf = nhs[n_nhs + i].path_weight * norm; /* use saved weights */
word n = flt_round_nearest (nf);
n = n > n_adj_left ? n_adj_left : n;
n_adj_left -= n;
error += fabs (nf - n);
nhs[i].path_weight = n;
if (0 == nhs[i].path_weight)
{
/*
* when the weight skew is high (norm is small) and n == nf.
* without this correction the path with a low weight would have
* no representation in the load-balanace - don't want that.
* If the weight skew is high so the load-balance has many buckets
* to allow it. pays ya money takes ya choice.
*/
error = n_adj;
break;
}
}
nhs[0].path_weight += n_adj_left;
/* Less than 5% average error per adjacency with this size adjacency block? */
if (error <= multipath_next_hop_error_tolerance*n_adj)
{
/* Truncate any next hops with zero weight. */
_vec_len (nhs) = i;
break;
}
}
done:
/* Save vector for next call. */
*normalized_next_hops = nhs;
*sum_weight_in = sum_weight;
return n_adj;
}
static load_balance_path_t *
load_balance_multipath_next_hop_fixup (const load_balance_path_t *nhs,
dpo_proto_t drop_proto)
{
if (0 == vec_len(nhs))
{
load_balance_path_t *new_nhs = NULL, *nh;
/*
* we need something for the load-balance. so use the drop
*/
vec_add2(new_nhs, nh, 1);
nh->path_weight = 1;
dpo_copy(&nh->path_dpo, drop_dpo_get(drop_proto));
return (new_nhs);
}
return (NULL);
}
/*
* Fill in adjacencies in block based on corresponding
* next hop adjacencies.
*/
static void
load_balance_fill_buckets_norm (load_balance_t *lb,
load_balance_path_t *nhs,
dpo_id_t *buckets,
u32 n_buckets)
{
load_balance_path_t *nh;
u16 ii, bucket;
bucket = 0;
/*
* the next-hops have normalised weights. that means their sum is the number
* of buckets we need to fill.
*/
vec_foreach (nh, nhs)
{
for (ii = 0; ii < nh->path_weight; ii++)
{
ASSERT(bucket < n_buckets);
load_balance_set_bucket_i(lb, bucket++, buckets, &nh->path_dpo);
}
}
}
static void
load_balance_fill_buckets_sticky (load_balance_t *lb,
load_balance_path_t *nhs,
dpo_id_t *buckets,
u32 n_buckets)
{
load_balance_path_t *nh, *fwding_paths;
u16 ii, bucket, fpath;
fpath = bucket = 0;
fwding_paths = NULL;
vec_foreach (nh, nhs)
{
if (!dpo_is_drop(&nh->path_dpo))
{
vec_add1(fwding_paths, *nh);
}
}
if (vec_len(fwding_paths) == 0)
fwding_paths = vec_dup(nhs);
/*
* the next-hops have normalised weights. that means their sum is the number
* of buckets we need to fill.
*/
vec_foreach (nh, nhs)
{
for (ii = 0; ii < nh->path_weight; ii++)
{
ASSERT(bucket < n_buckets);
if (!dpo_is_drop(&nh->path_dpo))
{
load_balance_set_bucket_i(lb, bucket++, buckets, &nh->path_dpo);
}
else
{
/* fill the bucks from the next up path */
load_balance_set_bucket_i(lb, bucket++, buckets, &fwding_paths[fpath].path_dpo);
fpath = (fpath + 1) % vec_len(fwding_paths);
}
}
}
vec_free(fwding_paths);
}
static void
load_balance_fill_buckets (load_balance_t *lb,
load_balance_path_t *nhs,
dpo_id_t *buckets,
u32 n_buckets,
load_balance_flags_t flags)
{
if (flags & LOAD_BALANCE_FLAG_STICKY)
{
load_balance_fill_buckets_sticky(lb, nhs, buckets, n_buckets);
}
else
{
load_balance_fill_buckets_norm(lb, nhs, buckets, n_buckets);
}
}
static inline void
load_balance_set_n_buckets (load_balance_t *lb,
u32 n_buckets)
{
lb->lb_n_buckets = n_buckets;
lb->lb_n_buckets_minus_1 = n_buckets-1;
}
void
load_balance_multipath_update (const dpo_id_t *dpo,
const load_balance_path_t * raw_nhs,
load_balance_flags_t flags)
{
load_balance_path_t *nh, *nhs, *fixed_nhs;
u32 sum_of_weights, n_buckets, ii;
index_t lbmi, old_lbmi;
load_balance_t *lb;
dpo_id_t *tmp_dpo;
nhs = NULL;
ASSERT(DPO_LOAD_BALANCE == dpo->dpoi_type);
lb = load_balance_get(dpo->dpoi_index);
lb->lb_flags = flags;
fixed_nhs = load_balance_multipath_next_hop_fixup(raw_nhs, lb->lb_proto);
n_buckets =
ip_multipath_normalize_next_hops((NULL == fixed_nhs ?
raw_nhs :
fixed_nhs),
&nhs,
&sum_of_weights,
multipath_next_hop_error_tolerance);
ASSERT (n_buckets >= vec_len (raw_nhs));
/*
* Save the old load-balance map used, and get a new one if required.
*/
old_lbmi = lb->lb_map;
if (flags & LOAD_BALANCE_FLAG_USES_MAP)
{
lbmi = load_balance_map_add_or_lock(n_buckets, sum_of_weights, nhs);
}
else
{
lbmi = INDEX_INVALID;
}
if (0 == lb->lb_n_buckets)
{
/*
* first time initialisation. no packets inflight, so we can write
* at leisure.
*/
load_balance_set_n_buckets(lb, n_buckets);
if (!LB_HAS_INLINE_BUCKETS(lb))
vec_validate_aligned(lb->lb_buckets,
lb->lb_n_buckets - 1,
CLIB_CACHE_LINE_BYTES);
load_balance_fill_buckets(lb, nhs,
load_balance_get_buckets(lb),
n_buckets, flags);
lb->lb_map = lbmi;
}
else
{
/*
* This is a modification of an existing load-balance.
* We need to ensure that packets inflight see a consistent state, that
* is the number of reported buckets the LB has (read from
* lb_n_buckets_minus_1) is not more than it actually has. So if the
* number of buckets is increasing, we must update the bucket array first,
* then the reported number. vice-versa if the number of buckets goes down.
*/
if (n_buckets == lb->lb_n_buckets)
{
/*
* no change in the number of buckets. we can simply fill what
* is new over what is old.
*/
load_balance_fill_buckets(lb, nhs,
load_balance_get_buckets(lb),
n_buckets, flags);
lb->lb_map = lbmi;
}
else if (n_buckets > lb->lb_n_buckets)
{
/*
* we have more buckets. the old load-balance map (if there is one)
* will remain valid, i.e. mapping to indices within range, so we
* update it last.
*/
if (n_buckets > LB_NUM_INLINE_BUCKETS &&
lb->lb_n_buckets <= LB_NUM_INLINE_BUCKETS)
{
/*
* the new increased number of buckets is crossing the threshold
* from the inline storage to out-line. Alloc the outline buckets
* first, then fixup the number. then reset the inlines.
*/
ASSERT(NULL == lb->lb_buckets);
vec_validate_aligned(lb->lb_buckets,
n_buckets - 1,
CLIB_CACHE_LINE_BYTES);
load_balance_fill_buckets(lb, nhs,
lb->lb_buckets,
n_buckets, flags);
CLIB_MEMORY_BARRIER();
load_balance_set_n_buckets(lb, n_buckets);
CLIB_MEMORY_BARRIER();
for (ii = 0; ii < LB_NUM_INLINE_BUCKETS; ii++)
{
dpo_reset(&lb->lb_buckets_inline[ii]);
}
}
else
{
if (n_buckets <= LB_NUM_INLINE_BUCKETS)
{
/*
* we are not crossing the threshold and it's still inline buckets.
* we can write the new on the old..
*/
load_balance_fill_buckets(lb, nhs,
load_balance_get_buckets(lb),
n_buckets, flags);
CLIB_MEMORY_BARRIER();
load_balance_set_n_buckets(lb, n_buckets);
}
else
{
/*
* we are not crossing the threshold. We need a new bucket array to
* hold the increased number of choices.
*/
dpo_id_t *new_buckets, *old_buckets, *tmp_dpo;
new_buckets = NULL;
old_buckets = load_balance_get_buckets(lb);
vec_validate_aligned(new_buckets,
n_buckets - 1,
CLIB_CACHE_LINE_BYTES);
load_balance_fill_buckets(lb, nhs, new_buckets,
n_buckets, flags);
CLIB_MEMORY_BARRIER();
lb->lb_buckets = new_buckets;
CLIB_MEMORY_BARRIER();
load_balance_set_n_buckets(lb, n_buckets);
vec_foreach(tmp_dpo, old_buckets)
{
dpo_reset(tmp_dpo);
}
vec_free(old_buckets);
}
}
/*
* buckets fixed. ready for the MAP update.
*/
lb->lb_map = lbmi;
}
else
{
/*
* bucket size shrinkage.
* Any map we have will be based on the old
* larger number of buckets, so will be translating to indices
* out of range. So the new MAP must be installed first.
*/
lb->lb_map = lbmi;
CLIB_MEMORY_BARRIER();
if (n_buckets <= LB_NUM_INLINE_BUCKETS &&
lb->lb_n_buckets > LB_NUM_INLINE_BUCKETS)
{
/*
* the new decreased number of buckets is crossing the threshold
* from out-line storage to inline:
* 1 - Fill the inline buckets,
* 2 - fixup the number (and this point the inline buckets are
* used).
* 3 - free the outline buckets
*/
load_balance_fill_buckets(lb, nhs,
lb->lb_buckets_inline,
n_buckets, flags);
CLIB_MEMORY_BARRIER();
load_balance_set_n_buckets(lb, n_buckets);
CLIB_MEMORY_BARRIER();
vec_foreach(tmp_dpo, lb->lb_buckets)
{
dpo_reset(tmp_dpo);
}
vec_free(lb->lb_buckets);
}
else
{
/*
* not crossing the threshold.
* 1 - update the number to the smaller size
* 2 - write the new buckets
* 3 - reset those no longer used.
*/
dpo_id_t *buckets;
u32 old_n_buckets;
old_n_buckets = lb->lb_n_buckets;
buckets = load_balance_get_buckets(lb);
load_balance_set_n_buckets(lb, n_buckets);
CLIB_MEMORY_BARRIER();
load_balance_fill_buckets(lb, nhs, buckets,
n_buckets, flags);
for (ii = n_buckets; ii < old_n_buckets; ii++)
{
dpo_reset(&buckets[ii]);
}
}
}
}
vec_foreach (nh, nhs)
{
dpo_reset(&nh->path_dpo);
}
vec_free(nhs);
vec_free(fixed_nhs);
load_balance_map_unlock(old_lbmi);
}
static void
load_balance_lock (dpo_id_t *dpo)
{
load_balance_t *lb;
lb = load_balance_get(dpo->dpoi_index);
lb->lb_locks++;
}
static void
load_balance_destroy (load_balance_t *lb)
{
dpo_id_t *buckets;
int i;
buckets = load_balance_get_buckets(lb);
for (i = 0; i < lb->lb_n_buckets; i++)
{
dpo_reset(&buckets[i]);
}
LB_DBG(lb, "destroy");
if (!LB_HAS_INLINE_BUCKETS(lb))
{
vec_free(lb->lb_buckets);
}
fib_urpf_list_unlock(lb->lb_urpf);
load_balance_map_unlock(lb->lb_map);
pool_put(load_balance_pool, lb);
}
static void
load_balance_unlock (dpo_id_t *dpo)
{
load_balance_t *lb;
lb = load_balance_get(dpo->dpoi_index);
lb->lb_locks--;
if (0 == lb->lb_locks)
{
load_balance_destroy(lb);
}
}
static void
load_balance_mem_show (void)
{
fib_show_memory_usage("load-balance",
pool_elts(load_balance_pool),
pool_len(load_balance_pool),
sizeof(load_balance_t));
load_balance_map_show_mem();
}
static u16
load_balance_dpo_get_mtu (const dpo_id_t *dpo)
{
const dpo_id_t *buckets;
load_balance_t *lb;
u16 i, mtu = 0xffff;
lb = load_balance_get(dpo->dpoi_index);
buckets = load_balance_get_buckets(lb);
for (i = 0; i < lb->lb_n_buckets; i++)
{
mtu = clib_min (mtu, dpo_get_mtu (&buckets[i]));
}
return (mtu);
}
const static dpo_vft_t lb_vft = {
.dv_lock = load_balance_lock,
.dv_unlock = load_balance_unlock,
.dv_format = format_load_balance_dpo,
.dv_mem_show = load_balance_mem_show,
.dv_get_mtu = load_balance_dpo_get_mtu,
};
/**
* @brief The per-protocol VLIB graph nodes that are assigned to a load-balance
* object.
*
* this means that these graph nodes are ones from which a load-balance is the
* parent object in the DPO-graph.
*
* We do not list all the load-balance nodes, such as the *-lookup. instead
* we are relying on the correct use of the .sibling_of field when setting
* up these sibling nodes.
*/
const static char* const load_balance_ip4_nodes[] =
{
"ip4-load-balance",
NULL,
};
const static char* const load_balance_ip6_nodes[] =
{
"ip6-load-balance",
NULL,
};
const static char* const load_balance_mpls_nodes[] =
{
"mpls-load-balance",
NULL,
};
const static char* const load_balance_l2_nodes[] =
{
"l2-load-balance",
NULL,
};
const static char* const load_balance_nsh_nodes[] =
{
"nsh-load-balance",
NULL
};
const static char* const load_balance_bier_nodes[] =
{
"bier-load-balance",
NULL,
};
const static char* const * const load_balance_nodes[DPO_PROTO_NUM] =
{
[DPO_PROTO_IP4] = load_balance_ip4_nodes,
[DPO_PROTO_IP6] = load_balance_ip6_nodes,
[DPO_PROTO_MPLS] = load_balance_mpls_nodes,
[DPO_PROTO_ETHERNET] = load_balance_l2_nodes,
[DPO_PROTO_NSH] = load_balance_nsh_nodes,
[DPO_PROTO_BIER] = load_balance_bier_nodes,
};
void
load_balance_module_init (void)
{
index_t lbi;
dpo_register(DPO_LOAD_BALANCE, &lb_vft, load_balance_nodes);
/*
* Special LB with index zero. we need to define this since the v4 mtrie
* assumes an index of 0 implies the ply is empty. therefore all 'real'
* adjs need a non-zero index.
* This should never be used, but just in case, stack it on a drop.
*/
lbi = load_balance_create(1, DPO_PROTO_IP4, 0);
load_balance_set_bucket(lbi, 0, drop_dpo_get(DPO_PROTO_IP4));
load_balance_logger =
vlib_log_register_class("dpo", "load-balance");
load_balance_map_module_init();
}
static clib_error_t *
load_balance_show (vlib_main_t * vm,
unformat_input_t * input,
vlib_cli_command_t * cmd)
{
index_t lbi = INDEX_INVALID;
while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
{
if (unformat (input, "%d", &lbi))
;
else
break;
}
if (INDEX_INVALID != lbi)
{
if (pool_is_free_index(load_balance_pool, lbi))
{
vlib_cli_output (vm, "no such load-balance:%d", lbi);
}
else
{
vlib_cli_output (vm, "%U", format_load_balance, lbi,
LOAD_BALANCE_FORMAT_DETAIL);
}
}
else
{
load_balance_t *lb;
pool_foreach (lb, load_balance_pool)
{
vlib_cli_output (vm, "%U", format_load_balance,
load_balance_get_index(lb),
LOAD_BALANCE_FORMAT_NONE);
}
}
return 0;
}
VLIB_CLI_COMMAND (load_balance_show_command, static) = {
.path = "show load-balance",
.short_help = "show load-balance [<index>]",
.function = load_balance_show,
};
always_inline u32
ip_flow_hash (void *data)
{
ip4_header_t *iph = (ip4_header_t *) data;
if ((iph->ip_version_and_header_length & 0xF0) == 0x40)
return ip4_compute_flow_hash (iph, IP_FLOW_HASH_DEFAULT);
else
return ip6_compute_flow_hash ((ip6_header_t *) iph, IP_FLOW_HASH_DEFAULT);
}
always_inline u64
mac_to_u64 (u8 * m)
{
return (*((u64 *) m) & 0xffffffffffff);
}
always_inline u32
l2_flow_hash (vlib_buffer_t * b0)
{
ethernet_header_t *eh;
u64 a, b, c;
uword is_ip, eh_size;
u16 eh_type;
eh = vlib_buffer_get_current (b0);
eh_type = clib_net_to_host_u16 (eh->type);
eh_size = ethernet_buffer_header_size (b0);
is_ip = (eh_type == ETHERNET_TYPE_IP4 || eh_type == ETHERNET_TYPE_IP6);
/* since we have 2 cache lines, use them */
if (is_ip)
a = ip_flow_hash ((u8 *) vlib_buffer_get_current (b0) + eh_size);
else
a = eh->type;
b = mac_to_u64 ((u8 *) eh->dst_address);
c = mac_to_u64 ((u8 *) eh->src_address);
hash_mix64 (a, b, c);
return (u32) c;
}
typedef struct load_balance_trace_t_
{
index_t lb_index;
} load_balance_trace_t;
always_inline uword
load_balance_inline (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * frame,
int is_l2)
{
u32 n_left_from, next_index, *from, *to_next;
from = vlib_frame_vector_args (frame);
n_left_from = frame->n_vectors;
next_index = node->cached_next_index;
while (n_left_from > 0)
{
u32 n_left_to_next;
vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
while (n_left_from > 0 && n_left_to_next > 0)
{
vlib_buffer_t *b0;
u32 bi0, lbi0, next0;
const dpo_id_t *dpo0;
const load_balance_t *lb0;
bi0 = from[0];
to_next[0] = bi0;
from += 1;
to_next += 1;
n_left_from -= 1;
n_left_to_next -= 1;
b0 = vlib_get_buffer (vm, bi0);
/* lookup dst + src mac */
lbi0 = vnet_buffer (b0)->ip.adj_index[VLIB_TX];
lb0 = load_balance_get(lbi0);
if (is_l2)
{
vnet_buffer(b0)->ip.flow_hash = l2_flow_hash(b0);
}
else
{
/* it's BIER */
const bier_hdr_t *bh0 = vlib_buffer_get_current(b0);
vnet_buffer(b0)->ip.flow_hash = bier_compute_flow_hash(bh0);
}
dpo0 = load_balance_get_bucket_i(lb0,
vnet_buffer(b0)->ip.flow_hash &
(lb0->lb_n_buckets_minus_1));
next0 = dpo0->dpoi_next_node;
vnet_buffer (b0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
{
load_balance_trace_t *tr = vlib_add_trace (vm, node, b0,
sizeof (*tr));
tr->lb_index = lbi0;
}
vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
n_left_to_next, bi0, next0);
}
vlib_put_next_frame (vm, node, next_index, n_left_to_next);
}
return frame->n_vectors;
}
static uword
l2_load_balance (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * frame)
{
return (load_balance_inline(vm, node, frame, 1));
}
static u8 *
format_l2_load_balance_trace (u8 * s, va_list * args)
{
CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
load_balance_trace_t *t = va_arg (*args, load_balance_trace_t *);
s = format (s, "L2-load-balance: index %d", t->lb_index);
return s;
}
/**
* @brief
*/
VLIB_REGISTER_NODE (l2_load_balance_node) = {
.function = l2_load_balance,
.name = "l2-load-balance",
.vector_size = sizeof (u32),
.format_trace = format_l2_load_balance_trace,
.n_next_nodes = 1,
.next_nodes = {
[0] = "error-drop",
},
};
static uword
nsh_load_balance (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * frame)
{
u32 n_left_from, next_index, *from, *to_next;
from = vlib_frame_vector_args (frame);
n_left_from = frame->n_vectors;
next_index = node->cached_next_index;
while (n_left_from > 0)
{
u32 n_left_to_next;
vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
while (n_left_from > 0 && n_left_to_next > 0)
{
vlib_buffer_t *b0;
u32 bi0, lbi0, next0, *nsh0;
const dpo_id_t *dpo0;
const load_balance_t *lb0;
bi0 = from[0];
to_next[0] = bi0;
from += 1;
to_next += 1;
n_left_from -= 1;
n_left_to_next -= 1;
b0 = vlib_get_buffer (vm, bi0);
lbi0 = vnet_buffer (b0)->ip.adj_index[VLIB_TX];
lb0 = load_balance_get(lbi0);
/* SPI + SI are the second word of the NSH header */
nsh0 = vlib_buffer_get_current (b0);
vnet_buffer(b0)->ip.flow_hash = nsh0[1] % lb0->lb_n_buckets;
dpo0 = load_balance_get_bucket_i(lb0,
vnet_buffer(b0)->ip.flow_hash &
(lb0->lb_n_buckets_minus_1));
next0 = dpo0->dpoi_next_node;
vnet_buffer (b0)->ip.adj_index[VLIB_TX] = dpo0->dpoi_index;
if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
{
load_balance_trace_t *tr = vlib_add_trace (vm, node, b0,
sizeof (*tr));
tr->lb_index = lbi0;
}
vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
n_left_to_next, bi0, next0);
}
vlib_put_next_frame (vm, node, next_index, n_left_to_next);
}
return frame->n_vectors;
}
static u8 *
format_nsh_load_balance_trace (u8 * s, va_list * args)
{
CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
load_balance_trace_t *t = va_arg (*args, load_balance_trace_t *);
s = format (s, "NSH-load-balance: index %d", t->lb_index);
return s;
}
/**
* @brief
*/
VLIB_REGISTER_NODE (nsh_load_balance_node) = {
.function = nsh_load_balance,
.name = "nsh-load-balance",
.vector_size = sizeof (u32),
.format_trace = format_nsh_load_balance_trace,
.n_next_nodes = 1,
.next_nodes = {
[0] = "error-drop",
},
};
static u8 *
format_bier_load_balance_trace (u8 * s, va_list * args)
{
CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
load_balance_trace_t *t = va_arg (*args, load_balance_trace_t *);
s = format (s, "BIER-load-balance: index %d", t->lb_index);
return s;
}
static uword
bier_load_balance (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * frame)
{
return (load_balance_inline(vm, node, frame, 0));
}
/**
* @brief
*/
VLIB_REGISTER_NODE (bier_load_balance_node) = {
.function = bier_load_balance,
.name = "bier-load-balance",
.vector_size = sizeof (u32),
.format_trace = format_bier_load_balance_trace,
.sibling_of = "mpls-load-balance",
};
// clang-format on